1993 Cadillac Eldorado V8-300 4.9LFACTORY OEM SERVICE PROCEDURE

Power Steering Pressure Switch: Testing and Inspection

Power Steering Pressure Switch:

Factory service manual diagram



Wiring Diagram:

Factory service manual diagram





Code P040 sets when vehicle speed is above 45 mph and the switch is open. See Trouble Code Charts for additional troubleshooting information.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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